On 30 September, 1971, Sergeant 2nd Class Riley and Senior Constable McDiarmid attended a dwelling in Mimosa Avenue, Toongabbie to investigate a report that a man had shot and killed his brother at that address. On arrival the police saw the offender RonaldClarke who quickly ran to the rear of the house. Senior Constable McDiarmid followed him while the sergeant entered through the front door. As the senior constable entered through the back door the offender opened fire with a shotgun, inflicting a fatal wound. It appears the offender then went back through the house where he also shot and killed Sergeant Riley. Although the senior constable was still alive when other police arrived he died a short time later in an ambulance on the way to hospital. The offender was shot and killed by police ( Cst 1/c Alf GREGORY ) the same day.

William Riley was born in 1921 and joined the New South Wales Police Force on 3 December, 1945. At the time of his death he was stationed at Blacktown. He was posthumously promoted to Sergeant 1st Class.

Maurice McDiarmid was born in 1932 and joined the New South Wales Police Force on 9 July, 1956. At the time of his death he was stationed at Blacktown. He was posthumously promoted to Sergeant 3rd Class.

George Lewis Memorial Trophy
This trophy for the year 1971, which is for the most courageous act performed by a member of the New South Wales Police Force, was awarded posthumously to the late Sergeant 1st Class W. W. Riley and the late Sergeant 3rd Class M. R. McDiarmid who were stationed at 27 Division.
The trophies were presented to Mrs Riley and Mrs McDiarmid at the Police Academy during 1972.

PETER MITCHELL TRUST AWARDS
The ten awards under this Trust for the year 1971 were made to the following police, the trophies being presented at the Police Academy during 1972:
Most Courageous Act Posthumously awarded to the late Sergeant 1st Class W. W. Riley and the late Sergeant 3rd Class M. R. McDiarmid in conjunction with the George Lewis Memorial Trophy.

Canberra Times (ACT : 1926 – 1995), Tuesday 21 March 1972, page 3

Plaque

SYDNEY, Monday. — At the Pine Grove Memorial Park near Rooty Hill today, Bishop Hulme-Moir, chaplain of the NSW Police Force, dedicated a plaque in memory of Sergeant Maurice McDiarmid and Sergeant William Riley, who were shot when attempting to arrest an armed man at Toongabbie on September 30 last year.

SYDNEY, Tuesday. -More than 400 policemen attended the funeral this morning of the two policemen shot by a man in Toongabbie last Thursday. Both men, Sergeant William Watson Riley and Senior Constable Maurice Raymond McDiarmid, were given full police honours at their funeral.

SYDNEY, Wednesday. – The NSW Government agreed today to make, as “an act of grace”, lump-sum payments of $12,500 to each of three police officers’ widows.

“The Premier, Sir Robert Askin, said the payments would be in addition to the pensions and dependant’s allowances already paid out of the police superannuation and reward fund.

The three policemen involved in the payments are Senior Constable W. E. King, who was murdered at East Gresford police station on August 13 last year, and Sergeants W. Riley and M. McDiarmid, who were shot by a man at Toongabbie on September 30 last year.

Sir Robert said members of the police force had always been specifically excluded from the definition of “worker” under the Workers Compensation Act.

He said the Commissioner of Police, Mr Allan, had brought to the notice of the Government that, in certain matters of workers’ compensation, police were in an anomalous position in relation to other Crown employees.

Sir Robert said a full examination would be made of overall benefits of workers’ compensation available to police.

SYDNEY, Friday. — A Sydney coroner has commended two policemen who chased and stopped “an armed and desperate man“.

The man, Mr Ronald Desmond Clarke, had earlier shot and killed two other policemen after having killed his own brother in Toongabbie on September 30.

The coroner, Mr J. Parnell, SM, found on Wednesday that Mr Clarke in turn died in a car of cerebral lacerations and gun shot wounds to the brain inflicted by a person defending himself.

Constable A. C. Gregory, giving evidence at the inquest into the deaths of the four men, said that he and Constable L. ( Les ) A. Crawford in a police truck had rammed Mr Clarke‘s car, causing him to lose control.

Constable Gregory had seen Mr Clarke transfer a gun from his left hand to his right. The gun had been pointing at the policeman’s face and the constable had fired “one shot towards his shoulder“.

“The impact of this bullet appeared to throw him towards the passenger side of his car, but he still had the revolver, which he now held in both hands, levelled at my face“, Constable Gregory said.

“He appeared to be endeavouring to discharge the gun and it was then that I fired two quick shots at him“.

The four men who were killed were Sergeant First Class William Watson Riley, 50, and Sergeant Maurice Raymond McDiarmid, 39, of Blacktown, and Ronald Desmond Clarke, 20, and Warren John Clarke, 22, both of Toongabbie.

( Both policemen were promoted posthumously. Sergeant Riley was raised from second-class to first class, and Sergeant McDiarmid from senior constable to sergeant third class. )

Mr Parnell found that Mr Warren John Clarke died from gunshot wounds inflicted by his brother, Mr Ronald Desmond Clarke.

He found also that Sergeant Riley died from a fractured skull and lacerations to the brain, and Sergeant McDiarmid died in an ambulance between Toongabbie and Blacktown Hospital.

Both died as a result of bullet wounds inflicted by Clarke.

He said Mr Ronald Clarke, a professional criminal, had shot his brother, Warren Clarke, after having raped his brother’s de facto wife.

POLICE KILLED OR WHO DIED FROM INJURIES RECEIVED IN THE EXECUTION OF THEIR DUTIES

On 13th August, 1971, Senior Constable William Edward King, who was then the officer-in-charge of police, East Gresford, was shot dead at East Gresford Police Station by a man who fired upon him with a rifle.

On 29th August, 1971, Constable 1st Class Patrick Mark Hackett died from injuries received in a motor accident at Polis, Cyprus, whilst performing duty with the New South Wales Police component of the Australian Police Contingent of the United Nations Peace Keeping Force.

On 30th September, 1971, Sergeant Second Class William Watson Riley and Senior Constable Maurice Raymond McDiarmid, both then attached to Blacktown Police Station, were shot dead in a house at Toongabbie which they had entered to arrest a man who a short time before had murdered his brother and raped a woman in the same house.

A police funeral with full ceremonial honours was accorded these deceased officers at which appropriate tributes were paid.

In recognition of their outstanding courage Sergeant Riley and Senior Constable McDiarmid were posthumously promoted by me to Sergeant 1st Class and Sergeant 3rd Class respectively. In addition, I submitted recommendations to the Premier for favour of consideration of Royal Awards being granted in both cases.

To assist the widows of the deceased police the Premier approved the payment to each of them of the sum of $12,500 as a gratuity. This payment did not in any way affect their entitlements to payments under the provisions of the Police Regulation (Superannuation) Act.